A) (4-c) + 2(c-3)=-13 б) -3(3b+1)-12=12
(4-с)+2(с-3)=-13 4-с+2с-6=-13 с=-13-4+6 с=-11 ====================== -3(3b+1)-12=12 -9b-3-12=12 -9b=12+3+12 -9b=27 b=27:(-9) b=-3